The following discussion sets forth the inventor's own knowledge of certain technologies and/or problems associated therewith. Accordingly, this discussion is not an admission of prior art, and it is not an admission of the knowledge available to a person of ordinary skill in the art.
The need for positive presence validation is quite a common task in a large variety of use cases that involve wireless communications. It is primarily a result of the fact that typically when a wireless medium is involved, peer devices can be physically located elsewhere (theoretically, anywhere in the network). There are use cases in which co-location of the parties is important and cannot be avoided. In these cases, mechanisms for ensuring device co-location are necessary. The various use cases may be clustered into several domains, including, but not limited to: (a) registration during authentication, (b) peer validation or verification, and (c) personalization or customization.
Registration during authentication ensures that the party involved in a registration or authentication procedure is indeed physically located in the close vicinity of one another and therefore may be trusted. An example of registration during authentication includes the initial pairing with an access point (AP) or with another peer (P2P) device. Peer validation or verification is another mechanism for presence detection. For instance, peer validation may be used for admission control, allowing only users at certain physical distance to gain access (e.g., a café hotspot that limits access to a certain range, rather than the full WiFi range). Personalization or customization involves the use of dynamically enabled services. For example, dynamically personalized data may be presented by a system if the system knows that the data is being observed by a relevant peer (e.g., a vending machine or other electronic terminal displays preferences or payment options specific to a nearby user).
Conventionally, proximity has been determined by causing a user to physically press a button on the peer device thereby proving physical access to it, or by asking that the user type a personal identification number (PIN) code or the like presented by the peer device as way of proving it is actually being observed by the user. Nowadays, proximity may also be determined using dedicated wireless communication technologies—e.g., Near Field Communications (NFC) or Radio Frequency Identification (RFID)—that are entirely distinct from the main wireless communication technology (e.g., WiFi, WiMAX, etc.).